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Diffstat (limited to 'runtime/JavaScript/src/org/antlr/runtime/RecognitionException.js')
| -rwxr-xr-x | runtime/JavaScript/src/org/antlr/runtime/RecognitionException.js | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/runtime/JavaScript/src/org/antlr/runtime/RecognitionException.js b/runtime/JavaScript/src/org/antlr/runtime/RecognitionException.js new file mode 100755 index 0000000..9c98605 --- /dev/null +++ b/runtime/JavaScript/src/org/antlr/runtime/RecognitionException.js @@ -0,0 +1,181 @@ +/** The root of the ANTLR exception hierarchy. + * + * <p>To avoid English-only error messages and to generally make things + * as flexible as possible, these exceptions are not created with strings, + * but rather the information necessary to generate an error. Then + * the various reporting methods in Parser and Lexer can be overridden + * to generate a localized error message. For example, MismatchedToken + * exceptions are built with the expected token type. + * So, don't expect getMessage() to return anything.</p> + * + * <p>ANTLR generates code that throws exceptions upon recognition error and + * also generates code to catch these exceptions in each rule. If you + * want to quit upon first error, you can turn off the automatic error + * handling mechanism using rulecatch action, but you still need to + * override methods mismatch and recoverFromMismatchSet.</p> + * + * <p>In general, the recognition exceptions can track where in a grammar a + * problem occurred and/or what was the expected input. While the parser + * knows its state (such as current input symbol and line info) that + * state can change before the exception is reported so current token index + * is computed and stored at exception time. From this info, you can + * perhaps print an entire line of input not just a single token, for example. + * Better to just say the recognizer had a problem and then let the parser + * figure out a fancy report.</p> + * + * @class + * @param {org.antlr.runtime.CommonTokenStream|org.antlr.runtime.tree.TreeNodeStream|org.antlr.runtime.ANTLRStringStream} input input stream that has an exception. + * @extends Error + * + */ +org.antlr.runtime.RecognitionException = function(input) { + org.antlr.runtime.RecognitionException.superclass.constructor.call(this); + this.input = input; + this.index = input.index(); + if ( input instanceof org.antlr.runtime.TokenStream ) { + this.token = input.LT(1); + this.line = this.token.getLine(); + this.charPositionInLine = this.token.getCharPositionInLine(); + } + if ( input instanceof org.antlr.runtime.tree.TreeNodeStream ) { + this.extractInformationFromTreeNodeStream(input); + } + else if ( input instanceof org.antlr.runtime.CharStream ) { + // Note: removed CharStream from hierarchy in JS port so checking for + // StringStream instead + this.c = input.LA(1); + this.line = input.getLine(); + this.charPositionInLine = input.getCharPositionInLine(); + } + else { + this.c = input.LA(1); + } + + this.message = this.toString(); +}; + +org.antlr.lang.extend(org.antlr.runtime.RecognitionException, Error, +/** @lends org.antlr.runtime.RecognitionException.prototype */ +{ + /** + * What input stream did the error occur in? + */ + input: null, + + /** What is index of token/char were we looking at when the error occurred? + * @type Number + */ + index: null, + + /** The current Token when an error occurred. Since not all streams + * can retrieve the ith Token, we have to track the Token object. + * For parsers. Even when it's a tree parser, token might be set. + * @type org.antlr.runtime.CommonToken + */ + token: null, + + /** If this is a tree parser exception, node is set to the node with + * the problem. + * @type Object + */ + node: null, + + /** The current char when an error occurred. For lexers. + * @type Number + */ + c: null, + + /** Track the line at which the error occurred in case this is + * generated from a lexer. We need to track this since the + * unexpected char doesn't carry the line info. + * @type Number + */ + line: null, + + /** The exception's class name. + * @type String + */ + name: "org.antlr.runtime.RecognitionException", + + /** Position in the line where exception occurred. + * @type Number + */ + charPositionInLine: null, + + /** If you are parsing a tree node stream, you will encounter som + * imaginary nodes w/o line/col info. We now search backwards looking + * for most recent token with line/col info, but notify getErrorHeader() + * that info is approximate. + * @type Boolean + */ + approximateLineInfo: null, + + /** Gather exception information from input stream. + * @param {org.antlr.runtime.CommonTokenStream|org.antlr.runtime.tree.TreeNodeStream|org.antlr.runtime.ANTLRStringStream} input input stream that has an exception. + */ + extractInformationFromTreeNodeStream: function(input) { + var nodes = input, + priorNode, + priorPayload, + type, + text, + i; + + this.node = nodes.LT(1); + var adaptor = nodes.getTreeAdaptor(), + payload = adaptor.getToken(this.node); + if ( payload ) { + this.token = payload; + if ( payload.getLine()<= 0 ) { + // imaginary node; no line/pos info; scan backwards + i = -1; + priorNode = nodes.LT(i); + while ( priorNode ) { + priorPayload = adaptor.getToken(priorNode); + if ( priorPayload && priorPayload.getLine()>0 ) { + // we found the most recent real line / pos info + this.line = priorPayload.getLine(); + this.charPositionInLine = priorPayload.getCharPositionInLine(); + this.approximateLineInfo = true; + break; + } + --i; + priorNode = nodes.LT(i); + } + } + else { // node created from real token + this.line = payload.getLine(); + this.charPositionInLine = payload.getCharPositionInLine(); + } + } + else if ( this.node instanceof org.antlr.runtime.tree.Tree) { + this.line = this.node.getLine(); + this.charPositionInLine = this.node.getCharPositionInLine(); + if ( this.node instanceof org.antlr.runtime.tree.CommonTree) { + this.token = this.node.token; + } + } + else { + type = adaptor.getType(this.node); + text = adaptor.getText(this.node); + this.token = new org.antlr.runtime.CommonToken(type, text); + } + }, + + /** Return the token type or char of the unexpected input element + * @return {Number} type of the unexpected input element. + */ + getUnexpectedType: function() { + if ( this.input instanceof org.antlr.runtime.TokenStream ) { + return this.token.getType(); + } + else if ( this.input instanceof org.antlr.runtime.tree.TreeNodeStream ) { + var nodes = this.input; + var adaptor = nodes.getTreeAdaptor(); + return adaptor.getType(this.node); + } + else { + return this.c; + } + } +}); |